Enabling Optomechanical Frequency Comb Through Thermal and Optical Forces in Nonlinear Nanomechanical Resonator

This paper reports a novel mechanism to generate frequency comb (FC) in optomechanical systems. FC is generated through a combination of thermo-optical effect and mechanical nonlinear frequency mixing process. The sidebands of the FC are produced from the overtone generation process. Additionally, a nonlinear nanomechanical resonator (NNR) is employed to introduce a frequency mixing process. We achieve a repetition rate of 80.1 kHz using a pump power of 0.082 mW. The carrier frequency of the optomechanical frequency comb (OMFC) is related to the nonlinear on-chip mechanical resonator, which is 4.3 MHz in our system. The footprint is reduced to 8.7 × 30μm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>.